Ensure to call superclass setUp/tearDown methods in mixin classes
More systematic use of TempFileMixin in test_array.py
Refactoring of test_attributes.py
Refactoring

* consistenc call of setUp/tearDown methods of the superclass
* use standardized names for hdf5 filename and file handle
* removed "from tables import *"
Update setup.py to use Cython.__version__
Update tables/tests/common.py to use Cython.__version__
Merge remote-tracking branch 'zyv/develop' into develop
Bump min_cython_version to 0.14